To assess the malignant potential of tongue cancer by intraoral ultrasonography, we examined 22 patients with squamous cell carcinoma of the tongue. Ultrasongraphic findings of the lesions were evaluated with respect to shape, border, internal echo, marginal echo, and depth of invasion (usD). Except for 3 tumors with a pathologic depth of invasion (pD) of less than 1 mm, 19 of 22 tumors (86.4%) were detected as hypoechoic lesions on intraoral ultrasonography. When the ultrasonographic and clinicopathologic findings were compared, tumors with diffuse invasion exhibited irregular shapes and diffuse borders on ultrasonography. Tumors with neck metastasis showed irregular shapes, diffuse borders, and hyperechoic marginal echoes. In addition, there was a significant correlation between usD and pD. Seven (58.3%) of 12 tumors with invasion of 8.0mm or more on ultrasonography were associated with neck metastasis.
In conclusion, intraoral ultrasonographic examination of tongue cancer provides information useful in evaluating tumor extent and malignant potential.